Dr. Andrew Weil: The depression-inflammation link

The dramatic rise in depression diagnoses over the last two decades is a great challenge to modern medicine. I believe that part of the “depression epidemic” is false — a creation of aggressive disease-mongering by pharmaceutical companies to promote antidepressant sales. However, it’s equally clear that within that trend, there has been a real rise in depression rates.

The reasons for the increase are complex, but one important theory deserves special consideration, because I believe it offers new possibilities for prevention and treatment. At the center of this theory are cytokines — proteins made by immune cells that govern responses to foreign antigens and germs.

Cytokines have varied effects. One type — the interleukins — controls inflammation and produces fever. Another type governs how red and white blood cells in the bone marrow mature. Because of such powerful effects, some cytokines have proved useful as medical treatments, though they can be quite toxic. In 1980, scientists succeeded in inserting a gene for human interferon into bacteria — this made it possible to mass-produce and purify these proteins. Since then, synthetic, injectable forms of interferon have been in wide use as treatments for several cancers (skin cancers, some leukemias), chronic viral hepatitis and multiple sclerosis.